CVS commit: src/lib/libc/time

["Christos Zoulas" <christos%netbsd.org@localhost>]

Module Name:    src
Committed By:   christos
Date:           Sat Oct 29 13:55:50 UTC 2022

Modified Files:
        src/lib/libc/time: Makefile NEWS localtime.c private.h theory.html
            version zdump.c zic.8 zic.c

Log Message:
Update to tzcode2022f

  Changes to code

    zic now supports links to links regardless of input line order.
    For example, if Australia/Sydney is a Zone, the lines
      Link Australia/Canberra Australia/ACT
      Link Australia/Sydney Australia/Canberra
    now work correctly, even though the shell commands
      ln Australia/Canberra Australia/ACT
      ln Australia/Sydney Australia/Canberra
    would fail because the first command attempts to use a link
    Australia/Canberra that does not exist until after the second
    command is executed.  Previously, zic had unspecified behavior if
    a Link line's target was another link, and zic often misbehaved if
    a Link line's target was a later Link line.

    Fix line number in zic's diagnostic for a link to a link.

    Fix a bug that caused localtime to mishandle timestamps starting
    in the year 2438 when reading data generated by 'zic -b fat' when
    distant-future DST transitions occur at times given in standard
    time or in UT, not the usual case of local time.  This occurs when
    the corresponding .zi Rule lines specify DST transitions with TO
    columns of 'max' and AT columns that end in 's' or 'u'.  The
    number 2438 comes from the 32-bit limit in the year 2038, plus the
    400-year Gregorian cycle.  (Problem reported by Bradley White.)

    On glibc 2.34 and later, which optionally supports 64-bit time_t
    on platforms like x86 where time_t was traditionally 32 bits,
    default time_t to 64 instead of 32 bits.  This lets functions like
    localtime support timestamps after the year 2038, and fixes
    year-2038 problems in zic when accessing files dated after 2038.
    To continue to limit time_t to 32 bits on these platforms, use
    "make CFLAGS='-D_TIME_BITS=32'".

    In C code, do not enable large-file support on platforms like AIX
    and macOS that no longer need it now that tzcode does not use
    off_t or related functions like 'stat'.  Large-file support is
    still enabled by default on GNU/Linux, as it is needed for 64-bit
    time_t support.

    In C code, prefer C23 keywords to pre-C23 macros for alignof,
    bool, false, and true.  Also, use the following C23 features if
    available: __has_include, unreachable.

    zic no longer works around Qt bug 53071, as the relevant Qt
    releases have been out of support since 2019.  This change affects
    only fat TZif files, as thin files never had the workaround.

    zdump no longer modifies the environ vector when compiled on
    platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
    This avoid undefined behavior on POSIX platforms.


To generate a diff of this commit:
cvs rdiff -u -r1.52 -r1.53 src/lib/libc/time/Makefile
cvs rdiff -u -r1.38 -r1.39 src/lib/libc/time/NEWS
cvs rdiff -u -r1.134 -r1.135 src/lib/libc/time/localtime.c
cvs rdiff -u -r1.60 -r1.61 src/lib/libc/time/private.h
cvs rdiff -u -r1.15 -r1.16 src/lib/libc/time/theory.html
cvs rdiff -u -r1.21 -r1.22 src/lib/libc/time/version
cvs rdiff -u -r1.57 -r1.58 src/lib/libc/time/zdump.c
cvs rdiff -u -r1.39 -r1.40 src/lib/libc/time/zic.8
cvs rdiff -u -r1.83 -r1.84 src/lib/libc/time/zic.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.